[MEDIUM] backend: initialize the server stream_interface upon connect()

It's not normal to initialize the server-side stream interface from the
accept() function, because it may change later. Thus, we introduce a new
stream_sock_prepare_interface() function which is called just before the
connect() and which sets all of the stream_interface's callbacks to the
default ones used for real sockets. The ->connect function is also set
at the same instant so that we can easily add new server-side protocols
soon.
diff --git a/src/backend.c b/src/backend.c
index 0e99879..1fc6b2a 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -35,9 +35,11 @@
 #include <proto/lb_fwrr.h>
 #include <proto/lb_map.h>
 #include <proto/proto_http.h>
+#include <proto/proto_tcp.h>
 #include <proto/queue.h>
 #include <proto/server.h>
 #include <proto/session.h>
+#include <proto/stream_sock.h>
 #include <proto/task.h>
 
 /*
@@ -902,8 +904,11 @@
 			return SN_ERR_INTERNAL;
 	}
 
-	if (!s->req->cons->connect)
-		return SN_ERR_INTERNAL;
+	/* Prepare the stream interface for a TCP connection. Later
+	 * we may assign a protocol-specific connect() function.
+	 */
+	stream_sock_prepare_interface(s->req->cons);
+	s->req->cons->connect = tcpv4_connect_server;
 
 	assign_tproxy_address(s);
 
diff --git a/src/stream_sock.c b/src/stream_sock.c
index 171ed29..9159796 100644
--- a/src/stream_sock.c
+++ b/src/stream_sock.c
@@ -1,7 +1,7 @@
 /*
  * Functions operating on SOCK_STREAM and buffers.
  *
- * Copyright 2000-2009 Willy Tarreau <w@1wt.eu>
+ * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -1221,6 +1221,17 @@
 	return 0;
 }
 
+/* Prepare a stream interface to be used in socket mode. */
+void stream_sock_prepare_interface(struct stream_interface *si)
+{
+	si->update = stream_sock_data_finish;
+	si->shutr = stream_sock_shutr;
+	si->shutw = stream_sock_shutw;
+	si->chk_rcv = stream_sock_chk_rcv;
+	si->chk_snd = stream_sock_chk_snd;
+	si->iohandler = NULL;
+}
+
 
 /*
  * Local variables: